ATMEGA8515-16AI Atmel, ATMEGA8515-16AI Datasheet - Page 52

• Manufacturer Part Number: ATMEGA8515-16AI
• Description: IC AVR MCU 8K 16MHZ IND 44-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8515-16AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

52
ATmega8515(L)
1. In the same operation, write a logic one to WDCE and WDE. A logic one must be
2. Within the next four clock cycles, write a logic 0 to WDE. This disables the
In safety level 2, it is not possible to disable the Watchdog Timer, even with the algo-
rithm described above. See “Timed Sequences for Changing the Configuration of the
Watchdog Timer” on page 53.
• Bits 2..0 – WDP2, WDP1, WDP0: Watchdog Timer Prescaler 2, 1, and 0
The WDP2, WDP1, and WDP0 bits determine the Watchdog Timer prescaling when the
Watchdog Timer is enabled. The different prescaling values and their corresponding
Timeout Periods are shown in Table 21.
Table 21. Watchdog Timer Prescale Select
The following code example shows one assembly and one C function for turning off the
WDT. The example assumes that interrupts are controlled (e.g., by disabling interrupts
globally) so that no interrupts will occur during execution of these functions.
Assembly Code Example
C Code Example
WDP2
0
0
0
0
1
1
1
1
written to WDE even though it is set to one before the disable operation starts.
Watchdog.
WDT_off:
void WDT_off(void)
{
}
; Write logical one to WDCE and WDE
ldi r16, (1<<WDCE)|(1<<WDE)
out WDTCR, r16
; Turn off WDT
ldi r16, (0<<WDE)
out WDTCR, r16
ret
/* Write logical one to WDCE and WDE */
WDTCR = (1<<WDCE) | (1<<WDE);
/* Turn off WDT */
WDTCR = 0x00;
WDP1
0
0
1
1
0
0
1
1
WDP0
0
1
0
1
0
1
0
1
1,024K (1,048,576)
2,048K (2,097,152)
Oscillator Cycles
Number of WDT
128K (131,072)
256K (262,144)
512K (524,288)
16K (16,384)
32K (32,768)
64K (65,536)
Typical Time-out
at V
17.1 ms
34.3 ms
68.5 ms
0.14 s
0.27 s
0.55 s
CC
1.1 s
2.2 s
= 3.0V
Typical Time-out
at V
16.3 ms
32.5 ms
2512K–AVR–01/10
65 ms
0.13 s
0.26 s
0.52 s
CC
1.0 s
2.1 s
= 5.0V